they help us connect. but little did we know, even when our phones are tucked away in our purses or pockets, we're still connecting and being tracked. every seven seconds, data from our phones is sent to cell towers, even when our phones are off. and what happens to that information? >> this information can tell police basically anything they want about the person. >> reporter: according to trevor tim of the electronic frontier foundation, law enforcement agencies are asking for gps contacts, and other data, and cell phone carriers like at&t and verizon are giving it away without your permission. >> there is actually what's called cell phone tower dumps where they're actually going after one person. but they end up getting information on everybody who had been around a cell phone tower during a certain amount of time. so even though they're only investigating one person, they now have information on hundreds or thousands of people. >> reporter: why are cell phone carriers giving your information away witho